Limit Analysis Of Weak Interlayer Slopes And Ultimate Bearing Capacity Of Rigid Pile Composite Foundation

The stability of slopes and ultimate bearing capacity of composite foundation are always the research hot spots in geotechnical engineering.Many research articles,which are focused on homogeneous slopes,had been published.When the weak layer depth is shallow and the soil parameters are low,the influences of the weak layer on the failure mode and the stability of the slope can't be ignored.The influence of the collapse of the pile on the ultimate bearing capacity of the reinforced ground has not been investigated deeply.These two problems are discussed in this paper by means of upper-bound theorem of limit analysis.(1)Two kinds of simple failure mechanisms,which is based on the study of other scholars,are established for the static case of the slope with weak intercalated layer.The validity and applicability of these mechanisms are verified by comparison with the classical conditions.(2)The stability analysis of the slopes with a single row anti-slide piles is carried out by way of upper-bound theorem of limit analysis and matlab program.The influence of the earthquake acceleration,the pile spacing and the pile body position on the safety factor,the surface of the slope and the permanent displacement are stated.(3)The limit analysis upper bound method for two dimensional and three-dimensional multi block mechanism is established.The 3D mechanism is further modified with a plane-strain central insert to ensure the transition to a plane-strain mechanism if no restraint is placed on the slope width.(4)A finite difference method was adopted to study the failure mode of the ground improved by the rigid pile.Based on the Tresca yield criterion and non-symmetric failure mechanism was proposed by upper-bound solution,which considered the contribution of the rigid pile.The optimal solution was obtained by the Monte Carlo Method.